R/W errors with SCSI CD drive

[amigakit]

Some CDRs have certain coatings that some lasers in CD drives dont read (hence the protracted seeking delay)

Not every CDR or CDRW will work on a given CD drive.  However professionally authored CDs should work nearly every time.

[pVC]

FrankBrana: Use scsiconfig program to set HD:s synchron and you can use myunitcontrol (from aminet) in user-startup to make cd:s synchron.

motorollin: leave caches on if you don't want slowdown in cpu It affects quite much. Only in extreme hopeless situation switch them off

[motorollin]

The discs I tested with were all prerecorded discs, not CD-Rs or CD-RWs, so the problem isn't media incompatibility.

I copied the CD0 mountlist that Matthew used to test the drive on to my 3.9 Emergency Disk and booted from it. It mounted successfully and could see the OS3.9 disc in the drive, but then read/write errors started coming up when it tried to access the disc.

Can I therefore conclude that this is not a software/configuration issue, but a hardware problem, either with the drive itself or with the SCSI chain?

--
moto

[Boot_WB]

Hi moto,

Have you tried increasing the number of buffers (eg to 150) in teh CDFS prefs on that drive?

[motorollin]

I'll try it now.

I went to Maplin and bought a 50 way active terminator, disabled the CD-RW's built in terminator, and terminated the chain after the CD-RW, but the same thing happened. So the only way this could be a termination problem is if the terminator in the controller isn't working.

--
moto

[motorollin]

Just tried changing buffers from 50 to 150, no change. Even added 1000 more to be sure, but it still doesn't work.

--
moto

[Boot_WB]

If you've got the original IDEfix97 program somewhere I'd seriously consider reinstalling it and allowing the program to pick up the drives when scanning the 1230scsi.device during installation.
I seem to remember having a similar problem on IDE - turned out I'd installed the CDrom as a scsi device rather than an atapi device.  Don't suppose that's much help here though.

[Amigaz]

Have you tried using another connector on the SCSI cable?
If it still fails your cd-rom got to be kaputtski

[motorollin]

@Boot_WB
I don't see how IDEfix will help - it's on a Blizzard SCSI controller, not a 4 way IDE interface  :-?

@Amigaz
I've tested it on every connector on the SCSI cable with the same result on all of them.

Amigakit are waiting for stock of the 50->68 way SCSI adapters, so once they have them I'll order one and an 18GB SCSI hard drive, which will test once and for all whether the SCSI chain is working.

--
moto

[Boot_WB]

Hi moto, don't worry, I've not gone IDE-SCSI loony :crazy: I suggested IDEfix as it seems to scan all devices on all buses, and seems to do a good job of mounting them OK (imho) - including PCMCIA and scsi.

Looking at your mountlist though, there seems to be no entry for STACK=xxxx .  THIS could account for your errors on larger files.  If Amigakit was using stackattack in his startup-sequence it wouldn't hav required it in the mountlist (AFAIK) but if you don't have stackattack in your startup this would make a difference.

I suggest you try putting a line in for "stacksize      =3000" (3000 is the recommended minimum) - on my CD mountfile it is after the "dostype     =" line.

[motorollin]

Cool, I'll try it. Is it stack=3000 or stacksize=3000?

--
moto

[motorollin]

[CLS2086]

Hi,
it's seems that your CD Drive was "frozen" durring the transport. Did you wait 5 hours before using it, that the grease on the pickup laserbeam motor unfreese ?
And how long is your SCSI chain (from the internal scsi card connector to the lastest element/terminator)?